Improvement of acoustic resistance equations in perforated plate absorbers with thin porous layers

2015 ◽  
Vol 63 (5) ◽  
pp. 415-423 ◽  
Author(s):  
Ivan Vican ◽  
Kristian Jambrosic ◽  
Hrvoje Domitrovic
Keyword(s):  
Perforated Plate ◽  
Porous Layers ◽  
Acoustic Resistance

scholarly journals A Perforated Plate with Stepwise Apertures for Low Frequency Sound Absorption

2021 ◽  
Vol 11 (13) ◽  
pp. 6180
Author(s):  
Xin Li ◽  
Bilong Liu ◽  
Chong Qin
Keyword(s):  
3D Printing ◽  
Sound Absorption ◽  
Numerical Models ◽  
Characteristic Impedance ◽  
Perforated Plate ◽  
Low Frequency ◽  
Low Frequencies ◽  
Perforated Plates ◽  
Absorption Bandwidth ◽  
Acoustic Resistance

A perforated plate with stepwise apertures (PPSA) is proposed to improve sound absorption for low frequencies. In contrast with an ordinary perforated plate with insufficient acoustic resistance and small acoustic mass, the perforated plate with stepped holes could match the acoustic resistance of air characteristic impedance and also moderately increase acoustic mass especially at low frequencies. Prototypes made by 3D printing technology are tested in an impedance tube. The measured results agree well with that of prediction through theoretical and numerical models. In addition, an absorber array of perforated plates with stepwise apertures is presented to extend the sound absorption bandwidth due to the introduced multiple local resonances.

scholarly journals ON NONLINEAR ACOUSTIC RESISTANCE OF A PERFORATED PLATE

1978 ◽  
Vol 27 (5) ◽  
pp. 600
Author(s):  
ZHAO SONG-LING ◽  
LU YUAN-WEI
Keyword(s):  
Perforated Plate ◽  
Acoustic Resistance ◽  
Nonlinear Acoustic

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Multiphysics Computational Analysis of a Perforated Plate Cooling Flow

2021 ◽  
Author(s):  
Justin M. Pesich ◽  
Nicholas J. Georgiadis ◽  
Mark P. Wernet
Keyword(s):  
Computational Analysis ◽  
Perforated Plate ◽  
Cooling Flow
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